This section is intended to introduce the reader to various aspects of the art that may be related to various aspects of the present invention. The following discussion is intended to provide information to facilitate a better understanding of the present invention. Accordingly, it should be understood that statements in the following discussion are to be read in this light, and not as admissions of prior art.
CSP (Concentrated Solar Power), particularly the parabolic trough utility scale facilities, are a proven source of renewable energy. Florida Power and Light operates a facility in the Mojave Desert which has operated for decades, which is based on a steel framework supporting the parabolic mirrors. Parabolic mirrors focus sunlight on an oil filled tube, and the hot oil is transferred to a conventional steam electrical power plant (the hot oil boils the water to steam, which drives the turbines).
Nevada Solar One (NSO) came on line a few years ago—the first new parabolic trough CSP plant in the US since the Mojave Desert installation. NSO used aluminum extrusions, fabricated and assembled into mirror support frames instead of structural steel. Continued installation of these types of CSP utility scale operations requires continual development in the technologies to improve performance and reduce costs.
The WES solar frame designs (see provisional patent applications U.S. 61/190,573 and 61/195,087, both of which are incorporated by reference herein) incorporate improvements in the extruded and other profiles and the way that they are combined into a framework to support the mirrors. These improvements yield a more efficient system—from profiles that are more easily extrudable at a wider variety of available extrusion operations through parts that are easily fabricated and assembled, utilizing the unique design opportunities provided by the aluminum extrusion process to enhance performance and reduce weight and cost of the final installation.
The description of the present invention, which follows incorporates further improvements to the WES designs, covering the strut, strut end piece and sleeve design enhancements which separately and together yield these improved designs, performance and costs.